1. Technical Field
The present invention relates to a latch apparatus, and more particularly, to a latch apparatus which allows a latch gear to be easily opened even by small force.
2. Description of the Related Art
Generally, in a latch apparatus for vehicles, a latch gear having a mounting groove and a pawl for restricting a locking end of the latch gear are rotatably disposed on a base plate having an opening.
The pawl receives rotational force from a handle and releases the latch gear from restriction, thereby allowing a door to be opened.
The latch gear includes a first locking portion and a second locking portion, thereby forming a two-stage locking condition in which the latch gear locking a striker is locked by the pawl.
When the striker enters the mounting groove of the latch gear, the latch gear rotates in one direction and the pawl is locked to the first locking portion of the latch gear, thereby forming a first locking stage.
When the latch gear is pushed by the striker and thus completely rotated, the pawl is locked to the second locking portion of the latch gear, thereby forming a second locking stage.
To move the latch gear from a locking location of the second locked state to a release location, releasing force is transmitted to the pawl such that the pawl can be separated from the latch gear.
If the pawl receiving manipulation force from the handle is separated from the latch gear, the latch gear is rotated in a releasing direction when opening force is applied to the door, thereby separating the striker from the latch gear.
A door seal is disposed along an edge of the door of the vehicle to block water and dust from entering the door.
The door seal is made of rubber and has elasticity. Thus, when the door is closed, the door seal applies force to the door in an opening direction.
In addition, the striker applies torque to the latch gear in a direction of releasing from the latch apparatus. The torque applied to the latch gear generates resistance to engagement between the latch gear and the pawl, thereby increasing a constraint force of the latch apparatus locking the striker increases.
A background technique of the present invention is disclosed in Korean Patent Publication No. 1998-0018831 (published on Jun. 5, 1998 and entitled “LATCH APPARATUS FOR VEHICLE REAR DOOR”).
When the door seal is compressed as the vehicle door is closed, the door is urged in an opening direction by restoring force of the door seal, thereby increasing torque transmitted to the latch gear. To release the pawl from the latch having the increased torque, a force for operating the pawl must also be increased, thereby making it difficult for old persons or the like to operate the handle and open the door. There, there is a need for a latch apparatus overcoming such a problem.